lib/bitmap: introduce bitmap_replace() helper

In some drivers we want to have a single operation over bitmap which is
an equivalent to:

	*dst = (*old & ~(*mask)) | (*new & *mask)

Introduce bitmap_replace() helper for this.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Bartosz Golaszewski <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Thomas Petazzoni <[email protected]>
Cc: William Breathitt Gray <[email protected]>
Cc: Yury Norov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index f9e834841e94..4250519d7d1c 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -222,6 +222,18 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 }
 EXPORT_SYMBOL(__bitmap_andnot);
 
+void __bitmap_replace(unsigned long *dst,
+		      const unsigned long *old, const unsigned long *new,
+		      const unsigned long *mask, unsigned int nbits)
+{
+	unsigned int k;
+	unsigned int nr = BITS_TO_LONGS(nbits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
+}
+EXPORT_SYMBOL(__bitmap_replace);
+
 int __bitmap_intersects(const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int bits)
 {